Conventionally, as the distributed power supply system of this kind, there is a home (in-house) power generation system disclosed in Patent Literature 1.
Hereinafter, a distributed power supply system disclosed in Patent Literature 1 will be described with reference to the drawings.
FIG. 10 is a block diagram of a conventional distributed power supply system disclosed as FIG. 1 in Patent Literature 1. Reference symbols depicted in FIG. 10 are changed from original ones by the applicant. As shown in FIG. 10, the conventional distributed power supply system includes current sensors 105a, 105b, a voltage sensor 106, a heater 107 and a control means 108. When an electric power value calculated from a current value detected by the current sensor 105a, 105b and a voltage value detected by the voltage sensor 106 is not more than a predetermined value, in a case where the heater 107 is actuated and a current flows in a state where a fuel cell system 104 is not generating electric power, the control means 108 inverts a positive/negative sign of the electric power value calculated thereafter.
This makes it possible to determine a direction in which the current sensor is installed and correct the electric power value, regardless of a state of the home load.
The determination as to the direction in which the current sensor 105a, 105b is installed may be performed plural times for the purpose of higher reliability.    Patent Literature 1: Japanese Laid-Open Patent Application Publication No. 2009-118673